Matthew Flatt wrote:
>> > Is there a Scheme function similar to "check-expect" that tests for
>> > equality between functions?
>> No.
>> Apologies if you already know this and I misunderstand the question,
> but: That's not the sort of thing that can be detected or proved in
> general. Look for information on the "halting problem" for details.
I'm surprised that you didn't mention that the very first problem to be
proved uncomputable, before the halting problem, was the problem of
equivalence of two expressions in the lambda calculus [Church 1936]. Of
course, understanding this via the halting problem is much simpler, and
that's the way we teach it nowadays. --PR